This invention relates to methods of processing incoming communications by a carrier (e.g., telecommunications service provider) or other intermediary on behalf of a subscriber. The communication can be, for example, incoming email or phone calls. The processing could take the form of diverting the call to voice mail, blocking the call or email, allowing the call to go through, or some other action. These actions can be viewed as filtering actions. More particularly, the invention relates to a method and system for processing incoming communications based on a “trust” or “reputation” score that is assigned to the communication (or, alternatively, to the source of the communication), and to methods for building a database of trust or reputation scores for use in filtering communications for subscribers. The trust scores are based on calling or emailing patterns of the source of the communication.
Filtering techniques for blocking unwanted junk email, also known as “spam,” are described in U.S. Pat. No. 6,654,787. The '787 patent describes a rules-based filtering approach in which a number of different filters apply different filtering criteria. These criteria include specific key words in the title or body of the email, a mathematical signature (e.g., a checksum), a virus checking filter; and an inclusion list (passing emails from previously approved sources). The patent further suggests that other filter modules could filter on the basis of word or letter frequency analysis, IP source frequency analysis, misspelling analysis, word or letter combination analysis, technical or legal RFC 822 header compliance, and feature extraction and analysis, e.g., based on phone numbers, URL's, addresses and so forth. U.S. Pat. No. 6,421,709 describes a similar method for filtering junk email based on user-specified email addresses or character strings which are in emails the user does not want to receive.
Screening and security related techniques directed specifically to telephone systems are disclosed in U.S. Pat. Nos. 5,604,791; 5,357,564 and 5,524,145.
Despite the advances represented in the above-referenced patent documents, the amount of unwanted messages seems to increase every year, particularly electronic messages such as spam. Furthermore, despite the advent of a national “do not call” list, unwanted calls from telemarketers, charities, and other organizations are still a recurring annoyance for many persons.
As technology has advanced over the last 10 years, portable communications devices such as wireless phones and similar devices have the capacity to communicate with third parties using a wide variety of technologies. These technologies include use of the cellular infrastructure to send and receive both voice calls as well as data calls (e.g., email messages), sending and receiving instant messages, sending and receiving messages in accordance with the Short Message Service (SMS) standard, and sending and receiving calls using the public switched telephone network via a base station that is connected to land line telephone circuits.
The present invention provides a more robust approach to call processing, e.g., screening and filtering, that uses “trust scores” for the communication, on the basis of inferences and assertions as to the relatedness of the parties to the communications or the likelihood that the communication is of interest to the recipient. The trust scores are determined from messaging patterns or possibly other indicia indicating a prior relatedness or relationship between of the parties. The invention is generally applicable to a variety of types of communication, and is not limited to email or voice. Moreover, the present invention allows a user to control the call screening function in a very simple manner using the trust scores, as described herein, without having to specify a large number character strings, key words, email addresses, and so forth in order to implement a screening filter. Additionally, because filters based on key words and character strings, they can be avoided relatively easily. Spammers are constantly changing their tactics to get through filters based on these strategies.
While the present invention described herein may be implemented in a completely stand alone fashion, it can also be used in combination with other screening devices and techniques, such as those described in the above-mentioned patent documents.